Related papers: The Olbers Conjecture, Revisited
Context. Reflected light from a spatially unresolved planet yields unique insight into the overall optical properties of the planet cover. Glories are optical phenomena caused by light that is backscattered within spherical droplets…
Dark stars powered by dark matter annihilation have been proposed as the first luminous sources in the universe. These stars are believed to form in the central dark matter cusp of low-mass minihalos. Recent calculations indicate stellar…
In this letter, we estimate how much starlight was absorbed by dust and released in the infrared during the formation of galaxies. New constraints are set on this so-far hidden history by the recent detection of the Cosmic Infrared…
The objective reality of the Earth's motion about the Sun was finally proven observationally by Bradley (1727) when he correctly explained the ~20'' annual, elliptical motions of stars as being due to aberration of starlight caused by the…
There is a longstanding discussion about whether low mass stars can form from pristine gas in the early Universe. A particular point of interest is whether we can find surviving pristine stars from the first generation in our local…
The hot big-bang cosmology provides a reliable accounting of the Universe from about $10^{-2}\sec$ after the bang until the present, as well as a robust framework for speculating back to times as early as $10^{-43}\sec$. Cosmology faces a…
The visual perception of the natural night sky in many places of the world is strongly disturbed by anthropogenic light. Part of this artificial light is scattered in the atmosphere and propagates towards the observer, adding to the natural…
We investigate the possibility of detecting artificial lights from Proxima b's dark side by computing light curves from the planet and its host star. The two different scenarios we consider are artificial illumination with the same spectrum…
Recent observations of hydrogen absorption that occurred when the first stars turned on may give insights into the nature of dark matter.
Since more than a century we investigate cosmic particles coming from the Universe with the aim of understanding their nature, their origin and how they are accelerated. So far, cosmic rays have provided many impressive results, giving…
Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…
The lens candidate CSL-1 has been interpreted as evidence for a cosmic string. Here we test the hypothesis that the lensing comes from a tidally disrupted dark matter halo. We calculate the mass-density relationship that one would expect…
Recent optical observations have led to a significant progress in our understanding of galaxy formation and evolution. However, our view on the deep universe is currently limited to the starlight which directly escapes from high-redshift…
Combinatorics is a powerful tool for dealing with relations among objectives mushroomed in the past century. However, an more important work for mathematician is to apply combinatorics to other mathematics and other sciences not merely to…
Presence of dust in galaxies removes half or more of the stellar energy from the UV-optical budget of the Universe and has profound impact on our understanding of how galaxies evolve. Measures of opacity in local galaxies are reviewed…
The initial conditions of our Universe can be summarized on a single sheet of paper. Yet the Universe is full of complex structures today, such as stars, galaxies and groups of galaxies. In this review I describe the standard theoretical…
The existence of multiple regions of space beyond the observable Universe (within the so-called "multiverse") where the vacuum energy density takes different values, has been postulated as an explanation for the low non-zero value observed…
High-contrast observations in optical and infrared astronomy are defined as any observation requiring a technique to reveal a celestial object of interest that is in such close angular proximity to another source brighter by a factor of at…
The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows…
An impressive bulk of multiple astronomical observations indicates that there are plenty of objects in the universe with the age which cannot be explained by the conventional theory. A model is considered which successfully describes all…